Diptera is one of the most diverse insect orders in the world, possibly ranking second or third in terms of estimated species diversity, and it requires a significant time investment in order to be studied even within one geographic area, with many new taxa being reported or described throughout the decades. This is the case for Bulgaria, where the systematized and extensive Catalog by Hubenov (2021) highlights the need for further research, creating a good baseline for future studies. We have caught or photographed multiple fly species new to the fauna of Bulgaria from multiple families, four of which are discussed here. The hyper-diverse family Empididae is represented by Rhamphomyia anfractuosa, collected from the region of Kyustendil. The family Micropezidae is represented by Rainieria calceata, which was observed and photographed near Vidin. From Rhinophoridae, Melanophora roralis was observed near Vidin and collected in the region of Sofia, where it is common in urban parks and green areas. From the family Sarcophagidae, the species confirmed to be among the fauna of Bulgaria are Sarcophaga belanovskyi and S. schusteri Lehrer, 1959. The former species was collected twice in the city of Sofia in 2022. It may have been previously reported under the name of S. ancilla, but these are currently considered to be separate species. Sarcophaga schusteri has been collected from different parts of Vitosha Mts in 2022 and 2023. Its taxonomic status is not fully clear, as it is similar to other montane taxa from the Alps. This species is likely not synonymous with Sarcophaga subvicina, as it was compared to material of S. subvicina from Czechia and Slovakia and shows differences. Povolny and Verves (1990) expressed suspicion about the older records of Sarcophaga subvicina in Bulgaria. This study is a part of the project under Grant contract number KP-06-N61/6 – 14.12.2022).